There are a number of issues regarding the Signal TLS proxy mentioned by PrivSec and others:
https://privsec.dev/posts/proxies/update-your-signal-tls-proxy/
https://www.privacyguides.org/articles/2022/10/15/warning-about-signal-proxies/
The second article linked has this recommendation, and I request PrivSec to have it as well:
Currently, we believe Signal’s TLS Proxies are an incomplete solution to the problems they try to solve. Instead, we recommend using Orbot in conjunction with Molly, an alternative Signal client which natively supports SOCKS proxies, to fully tunnel your Signal traffic over the Tor network.